This Node is a personal computing device, such as a PC, supporting a commercial browser (e.g. Netscape Navigator or Internet Explorer). The level of the browser is expected to support SSL and some level of DHTML. Most online buying implementations will send a "Cookie" to the browser on this node in order to maintain the shopping session. The cookie will contain a session id, which can be used to reconnect with a partially filled shopping basket or order and to re-establish the conversation for each interaction.

Firewalls provide services that can be used to control access from a less trusted network to a more trusted network. Traditional implementations of firewall services include:

• Screening routers (the protocol firewall in this design)
• Application gateways (the domain firewall)

The two firewall nodes provide increasing levels of protection at the expense of increasing computing resource requirements. The protocol firewall is typically implemented as an IP router, while the domain firewall is a dedicated server node.

Additional Resources

• (in English) ESS

The load balancer, or dispatcher, node provides horizontal scalability by dispatching HTTP requests among several, identically configured Web servers.

See Also

• Load balancer
• Transactional Web server

Additional Resources

• (in English) ESS

This node provides the infrastructure for application logic and can be part of a commerce server node. It is capable of running both presentation and business logic.

Firewalls provide services that can be used to control access from a less trusted network to a more trusted network. Traditional implementations of firewall services include:

• Screening routers (the protocol firewall in this design)
• Application gateways (the domain firewall)

The two firewall nodes provide increasing levels of protection at the expense of increasing computing resource requirements. The protocol firewall is typically implemented as an IP router, while the domain firewall is a dedicated server node.

Additional Resources

• (in English) ESS

Existing applications are run and maintained on nodes that are installed in the internal network. These applications provide for business logic that uses data maintained in the internal network. The number and topology of these existing application and data nodes is dependent on the particular configuration used by these legacy systems.

The database server node's function is to provide persistent data storage and retrieval in support of the user-to-business transactional interaction. The data stored is relevant to the specific business interaction, for example, bank balance, insurance information, current purchase by the user, and so forth.

Note that the mode of database access is perhaps the most important factor determining the performance of this Web application, in all but the simplest cases. The recommended approach is to collapse the database accesses into a single call or very few calls. This can be achieved through coding and invoking stored procedure calls on the database.

This node represents the functionality supporting the creation of the data that resides on the Database Server and Commerce Server Nodes. It also represents the function to manage and stage that data into production on the servers. The functionality of this node is quite broad, and might be thought of as encompassing an entire subsystem.

The timely synchronization of several Web Servers is sometimes achieved by using a Shared File System as the content storage, capitalizing on the replication capability of this technology.

A process that supports the use and management of Web pages and other Internet-related material.